dh_lib.c revision 296341 
1/* crypto/dh/dh_lib.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59#include <stdio.h>
60#include "cryptlib.h"
61#include <openssl/bn.h>
62#include <openssl/dh.h>
63#ifndef OPENSSL_NO_ENGINE
64# include <openssl/engine.h>
65#endif
66
67#ifdef OPENSSL_FIPS
68# include <openssl/fips.h>
69#endif
70
71const char DH_version[] = "Diffie-Hellman" OPENSSL_VERSION_PTEXT;
72
73static const DH_METHOD *default_DH_method = NULL;
74
75void DH_set_default_method(const DH_METHOD *meth)
76{
77    default_DH_method = meth;
78}
79
80const DH_METHOD *DH_get_default_method(void)
81{
82    if (!default_DH_method) {
83#ifdef OPENSSL_FIPS
84        if (FIPS_mode())
85            return FIPS_dh_openssl();
86        else
87            return DH_OpenSSL();
88#else
89        default_DH_method = DH_OpenSSL();
90#endif
91    }
92    return default_DH_method;
93}
94
95int DH_set_method(DH *dh, const DH_METHOD *meth)
96{
97    /*
98     * NB: The caller is specifically setting a method, so it's not up to us
99     * to deal with which ENGINE it comes from.
100     */
101    const DH_METHOD *mtmp;
102    mtmp = dh->meth;
103    if (mtmp->finish)
104        mtmp->finish(dh);
105#ifndef OPENSSL_NO_ENGINE
106    if (dh->engine) {
107        ENGINE_finish(dh->engine);
108        dh->engine = NULL;
109    }
110#endif
111    dh->meth = meth;
112    if (meth->init)
113        meth->init(dh);
114    return 1;
115}
116
117DH *DH_new(void)
118{
119    return DH_new_method(NULL);
120}
121
122DH *DH_new_method(ENGINE *engine)
123{
124    DH *ret;
125
126    ret = (DH *)OPENSSL_malloc(sizeof(DH));
127    if (ret == NULL) {
128        DHerr(DH_F_DH_NEW_METHOD, ERR_R_MALLOC_FAILURE);
129        return (NULL);
130    }
131
132    ret->meth = DH_get_default_method();
133#ifndef OPENSSL_NO_ENGINE
134    if (engine) {
135        if (!ENGINE_init(engine)) {
136            DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
137            OPENSSL_free(ret);
138            return NULL;
139        }
140        ret->engine = engine;
141    } else
142        ret->engine = ENGINE_get_default_DH();
143    if (ret->engine) {
144        ret->meth = ENGINE_get_DH(ret->engine);
145        if (!ret->meth) {
146            DHerr(DH_F_DH_NEW_METHOD, ERR_R_ENGINE_LIB);
147            ENGINE_finish(ret->engine);
148            OPENSSL_free(ret);
149            return NULL;
150        }
151    }
152#endif
153
154    ret->pad = 0;
155    ret->version = 0;
156    ret->p = NULL;
157    ret->g = NULL;
158    ret->length = 0;
159    ret->pub_key = NULL;
160    ret->priv_key = NULL;
161    ret->q = NULL;
162    ret->j = NULL;
163    ret->seed = NULL;
164    ret->seedlen = 0;
165    ret->counter = NULL;
166    ret->method_mont_p = NULL;
167    ret->references = 1;
168    ret->flags = ret->meth->flags & ~DH_FLAG_NON_FIPS_ALLOW;
169    CRYPTO_new_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
170    if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
171#ifndef OPENSSL_NO_ENGINE
172        if (ret->engine)
173            ENGINE_finish(ret->engine);
174#endif
175        CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, ret, &ret->ex_data);
176        OPENSSL_free(ret);
177        ret = NULL;
178    }
179    return (ret);
180}
181
182void DH_free(DH *r)
183{
184    int i;
185    if (r == NULL)
186        return;
187    i = CRYPTO_add(&r->references, -1, CRYPTO_LOCK_DH);
188#ifdef REF_PRINT
189    REF_PRINT("DH", r);
190#endif
191    if (i > 0)
192        return;
193#ifdef REF_CHECK
194    if (i < 0) {
195        fprintf(stderr, "DH_free, bad reference count\n");
196        abort();
197    }
198#endif
199
200    if (r->meth->finish)
201        r->meth->finish(r);
202#ifndef OPENSSL_NO_ENGINE
203    if (r->engine)
204        ENGINE_finish(r->engine);
205#endif
206
207    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DH, r, &r->ex_data);
208
209    if (r->p != NULL)
210        BN_clear_free(r->p);
211    if (r->g != NULL)
212        BN_clear_free(r->g);
213    if (r->q != NULL)
214        BN_clear_free(r->q);
215    if (r->j != NULL)
216        BN_clear_free(r->j);
217    if (r->seed)
218        OPENSSL_free(r->seed);
219    if (r->counter != NULL)
220        BN_clear_free(r->counter);
221    if (r->pub_key != NULL)
222        BN_clear_free(r->pub_key);
223    if (r->priv_key != NULL)
224        BN_clear_free(r->priv_key);
225    OPENSSL_free(r);
226}
227
228int DH_up_ref(DH *r)
229{
230    int i = CRYPTO_add(&r->references, 1, CRYPTO_LOCK_DH);
231#ifdef REF_PRINT
232    REF_PRINT("DH", r);
233#endif
234#ifdef REF_CHECK
235    if (i < 2) {
236        fprintf(stderr, "DH_up, bad reference count\n");
237        abort();
238    }
239#endif
240    return ((i > 1) ? 1 : 0);
241}
242
243int DH_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
244                        CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func)
245{
246    return CRYPTO_get_ex_new_index(CRYPTO_EX_INDEX_DH, argl, argp,
247                                   new_func, dup_func, free_func);
248}
249
250int DH_set_ex_data(DH *d, int idx, void *arg)
251{
252    return (CRYPTO_set_ex_data(&d->ex_data, idx, arg));
253}
254
255void *DH_get_ex_data(DH *d, int idx)
256{
257    return (CRYPTO_get_ex_data(&d->ex_data, idx));
258}
259
260int DH_size(const DH *dh)
261{
262    return (BN_num_bytes(dh->p));
263}
264